1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a multi-bit magnetic memory device using a spin-polarized current, and methods of manufacturing and operating the same.
2. Description of the Related Art
One area of study in related art magnetic memory devices pertains to ways to decrease the operation current of the magnetic memory device, reduce the magnetic influence on other adjacent devices when accessing a selected device, and guarantee structural magnetic stability of the device. Accordingly, unlike early magnetic memory devices in which a magnetic field was used to record bit data, magnetic memory devices using spin-polarization characteristics of a current for recording bit data have been introduced.
FIGS. 1 through 4 illustrate related art magnetic memory devices using spin-polarization of electrons to record data. Since the related art magnetic memory devices use electron spin, they are advantageous in that they can precisely select cells compared to the early magnetic memory devices using a magnetic field, but disadvantageous in that magnetic coupling between a free magnetic layer and a lower magnetic layer is weak. In addition, the related art magnetic memory devices have material layers decreasing the density of spin-polarized electrons, thereby requiring more current for a normal operation. Therefore, the use of the above-described related art magnetic memory devices may be difficult.